Dear PowerForum users,

I wanted to ask for some advice, please.

I have a Deye 5kW inverter with two Dyness BX51100 5kW batteries (200Ah) running perfectly for the past year.

My Deye inverter is set to 200Ah on the battery setting.

My installer installed another Dyness BX5110 today, so now I have three of the exact same batteries with a total of 300Ah battery capacity.

My installer said that on my Deye inverter settings the battery must not be adjusted to 300Ah, it must stay on 200Ah.

He spoke to his distributor to confirm this setting.

Is this best practice?

Insights on this will be much appreciated.

Maybe someone else knows better, but this sounds strange. What is the Li-BMS screen reporting? Basically, nevermind the Deye's manual settings, is the battery communicating that you've got 300Ah installed?

Just took these photos - not seeing anything saying 300Ah.

1 hour ago, Jan.Nel said:

My installer said that on my Deye inverter settings the battery must not be adjusted to 300Ah, it must stay on 200Ah.
 

Since you're using Li-BMS mode, the Capacity you specify in Ah doesn't actually get used. If you swap to AGM%, then the inverter will use the value to calculate SOC (in my experience it's pretty accurate as well).

Instead in your case, the battery BMS will handle it for you.

 

However something else doesn't look right: if each battery has a 'Recommended Discharge Current' of 50A, then three batteries should be higher than the 50A limit we see on-screen. Perhaps check that the comms between batteries (and also the dip switches that give each battery the correct role: i.e., master vs slave) are correct according to the manual?

Edited May 10, 20242 yr by JayMardern

1 hour ago, Jan.Nel said:

Just took these photos - not seeing anything saying 300Ah.

This value - Discharge Limit: 50A - is suggesting that the BMS is only recognising one battery connected.

Try this: On the inverter's Battery Settings, make sure the discharge current is 100A. Then disconnect the grid, ie. just turn off the mains switch. Next turn of the PV switch on the underside of the inverter. Then try to run around 3-4kW of appliances from battery only. A kettle and a toaster turned on at the same time should do it.

I'm suspecting your system will trip out with a DC fault at around 2.5kW load, which would suggest that the battery installation is incorrect, maybe dip switches or something like that.

I could be very wrong. Dalk weet hulle wat ek nie weet nie.

Hi Jan

Looks like the added batteries are not in communication with the inverter (see attached pics of mine with 1, 2 and 3 batteries in service)

It update the displayed value automatically.  Most likely dip switch settings issues.

Thanks @GreenFields, @JayMardern and @Oom Tas,

I think you all pointed me in the right direction here.

I've looked at the battery dip switches now and I've mapped them out below.

Current Battery 1:

1 - down
2 - down
3 - up
4 - down

Current Battery 2:

1 - down
2 - up
3 - down
4 - down

Current Battery 3:

1 - down
2 - up
3 - up
4 - down

By comparing this to the Dyness manual, it looks like they configured it as "Master 1, Master 2 and Master 3" for all the different inverter manufacturers 😲

Shouldn't it have been Master 1 (Deye), Slave, Slave?

In other words, my settings must look like the below?

Proposed Battery 1: (Master-1 for Deye inverter):

1 - down
2 - down
3 - up
4 - down

Proposed Battery 2 (Slave):

1 - down
2 - down
3 - down
4 - down

Proposed Battery 3(Slave):

1 - down
2 - down
3 - down
4 - down

 

Edited May 11, 20242 yr by Jan.Nel

So...I did more searches and research, and I believe the dip switch configs are incorrect.

I have followed the "solar system shutdown procedure" and switched the entire system off.

Changed the dip switches correctly for Deye & Dyness for Master/Slave according to the Manual, followed the "solar system start-up procedure" and got the system up and running.

Now my Li-BMS is reporting much better - Charge & Discharge current is 150A and 150A 🙌

Thank you guys 😅

Edited May 11, 20242 yr by Jan.Nel

12 minutes ago, Jan.Nel said:

Now my Li-BMS is report much better - Charge & Discharge current is 150A and 150A 🙌

Glad to hear it's sorted, so 300Ah is fine to note as your installed capacity. Only obvious last comment is that the inverter has its own max charge/discharge rate of 115A if I recall, so you could just check that that limit value and insert it (or even a touch less) is set on the inverter's Battery Settings screen.

Uitstekend. Ek het selwers na die manual gekyk en dit is nie 'straight forward' nie.   

Fully aggree with GreenFields

@GreenFields and @Oom Tas - Thanks guys, really appreciate your help and insights 👍 Bitter baie dankie. 😎

Based off this screen, it is limited to 50A (Charge) and 75A (Discharge) - probably defaults.

From the Deye manual, it looks like 120A maximum for the inverter.

What would your recommendations be?

22 minutes ago, Jan.Nel said:

@GreenFields and @Oom Tas - Thanks guys, really appreciate your help and insights 👍 Bitter baie dankie. 😎

Based off this screen, it is limited to 50A (Charge) and 75A (Discharge) - probably defaults.

From the Deye manual, it looks like 120A maximum for the inverter.

What would your recommendations be?

Maybe double-check with your installer first what battery cable sizes and fuses, etc. are in place. Just looking at the inverter and batteries, personally I'd go with 100A charge and 115A discharge, but that's not gold-standard values.

5 hours ago, Jan.Nel said:

By comparing this to the Dyness manual, it looks like they configured it as "Master 1, Master 2 and Master 3" for all the different inverter manufacturers 🤯

Shouldn't it have been Master 1 (Deye), Slave, Slave?

In other words, my settings must look like the below?

Proposed Battery 1: (Master-1 for Deye inverter):

1 - down
2 - down
3 - up
4 - down

Proposed Battery 2 (Slave):

1 - down
2 - down
3 - down
4 - down

Proposed Battery 3(Slave):

1 - down
2 - down
3 - down
4 - down

Yes, this is the correct settings.  Remember to power down the system before changing the Dip switch settings

I apologize, I am slow 😆

 

 

 

Edited May 11, 20242 yr by CobusK

4 hours ago, GreenFields said:

Maybe double-check with your installer first what battery cable sizes and fuses, etc. are in place. Just looking at the inverter and batteries, personally I'd go with 100A charge and 115A discharge, but that's not gold-standard values.

Thanks @GreenFields.

It looks like 25mm thick cable between batteries and towards the inverter.

My cabling is very neat, tidy and properly done. Cable trunking between everything.

Battery fuses are 125A each on positive & negative connections.

For now, I've set the following:

Max discharge current = 75 A
Max charge current = 50 A

Thanks again to all for the advice & insights.

How do i adjust the battery capacity on the 5kw Deye Inverter after connecting 2 48V aberdare batteries in parallel.. The inverter is recognising one battery and cutting of at 20%  [email protected]